<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .box {
      /* height: 200px; */
      /* overflow: hidden; */
      border: 2px solid #000;
      background-color: rgb(33, 187, 59);

    }

    .box1 {
      float: left;
      width: 100px;
      height: 100px;
      background-color: rgb(218, 221, 24);
    }

    .box2 {
      float: left;
      width: 100px;
      height: 100px;
      background-color: rgb(13, 157, 223);
    }

    .clearfix::after {
      content: '';
      display: block;
      clear: both;
    }
  </style>
</head>

<body>
  <div class="bb">
    <div class="box">
      <div class="box1"></div>
      <div class="box2"></div>
      <div class="clearfix"></div>
    </div>
    <div>123</div>
  </div>
</body>

</html>